A new stilbene glycoside, 5-methoxy-(E)-resveratrol 3-O-rutinoside (1) was isolated from the root bark of Elephantorrhiza goetzei, along with known compounds, namely gallic acid, (E)-resveratrol, (+/-)-catechin, (+/-)-gallocatechin and oleanene triterpenoids. The combined ethyl acetate-methanol extract exhibited high lethality against brine shrimp larvae (LC(50) 10.8 ppm) compared to the isolates, some of which were not active.